Quarterback Jay Cutler and the undefeated Chicago Bears walked into Ford Field with a shot to give themselves a commanding two-game lead in the NFC North.

Cutler, fresh off a critic-silencing performance during a bigSunday Night Football victory over the Pittsburgh Steelers, looked to continue the Bears' three-game win streak against the Lions.

Mike DiNovo-USA TODAY Sports

Instead, Cutler had one of the worst games of his career, and the Bears suffered a brutal loss. Cutler threw three interceptions and lost a fumble that was returned for a touchdown in a game that finished 40-32, but it wasn't anywhere near that close.

First-year skipper Marc Trestman has suffered defeat, and it's hard to imagine a more deflating one. In one week, the Bears went from surprise Super Bowl contenders to a team with a mess of problems. Or really, one problem that spawns a bunch of others: Cutler.

An Ill Wind

Trestman was hired to take Cutler's game to the next level; if he can't reach it, he won't get the contract extension he needs to stay in Chicago.

The warning signs about Cutler were there in the preseason. In Week 2, Cutler struggled against the rebuilding San Diego Chargers, targeting security blanket wide receiver Brandon Marshall on all five of his pass attempts.

Four of them were caught for 38 yards, but the other attempt was a terrible interception, which Cutler heaved at a double-covered Marshall.

Marshall gives Cutler and the Bears a reliable No. 1 target who can get open against almost any defense. Cutler's overreliance on Marshall seemed to make the Bears offense less efficient last season, though, and a return to staring him down spelled bad news for Bears this season.

Cutler's all-important third preseason game wasn't much better; he completed just 12 of 21 passes against the unimposing Oakland Raiders defense, for 6.8 yards per attempt. Cutler finished the preseason with two touchdowns, two interceptions, three sacks and just an 80.0 passer rating.

Cutler calmly executed the offense, letting players like Marshall and running back Matt Forte do the dirty work. The Bears gutted out three tough, important wins against the Cincinnati Bengals, Minnesota Vikings and Pittsburgh Steelers.

Going into the Lions game, four different Bears already had double-digit receptions: Marshall, Forte, Alshon Jeffery and tight end Martellus Bennett. Three different Bears had already hauled in touchdown passes: Marshall, Bennett and Earl Bennett.

Bennett, the Bears' big free-agent addition, finally gave Cutler a big red-zone target besides Marshall, and Cutler learned how to use him right away.

Jonathan Daniel/Getty Images

Best of all, Jay Cutler seemed to have complete buy-in; his old-school, shoulder-lowering first-down run against the Steelers was the kind of thing most never thought they'd see from the laconic Cutler.

With first-round draft pick Kyle Long anchoring the much-improved offensive line, it looked as though Trestman had successfully re-tooled Cutler, and the Bears offense around him.

Cutler then lobbed it up to a double-covered Marshall for his second interception, snared by safety Glover Quin. Again targeting Jeffery down the middle of the field, Cutler had this ball sail on him, and Delmas was there to snake his second interception of the day.

Though Cutler was sacked only three times on the day, one of those was a strip-sack by Lions defensive tackle Ndamukong Suh, recovered and returned for a touchdown by his partner-in-crime, Nick Fairley:

Every quarterback turns it over sometimes, but in a critical division rivalry game with so much at stake, four turnovers (leading to 17 Lions points) is unacceptable.

Fairly or not, Cutler's reputation as a player who'll excel right up until his team really needs him will be reinforced by this performance. With quarterbacks like Joe Flacco, Tony Romo and Matthew Stafford all signing massive contract extensions this offseason, Cutler needs to prove he's that kind of eight-digit-per-year money.

Surrendering the ball four times in a game with these kind of playoff implications should give the Bears' decision-makers nightmares about cutting Cutler that big of a check.

Playoff Forecast

Of course, Week 4 seems early to be talking playoffs. The Bears' season is now just a quarter through, though, and Sunday's game represented a massive swing in the Bears' playoff chances.

It's not just that the Bears lost a chance to go up a couple games on the Lions and 2.5 games on the Green Bay Packers. In a division as seemingly tight as the NFC North, tiebreakers will certainly loom large.

Now the Bears can only hope to get a split—and the Lions could sweep the series. The next major tiebreaker? Division record, which the Lions now hold a one-game edge in.

Going forward, Cutler and the Bears are sure to put up a lot of points, and win a lot of games. At the end of the day, though, his teammates have to believe that days like today won't happen.

Leon Halip/Getty Images

"He's just ice cold, man," Marshall told CBS Chicago after the Bears' big win over the Vikings. Marshall said at the time he calls Cutler "Mr. Fourth Quarter."

Indeed, Cutler led a frenetic garbage-time comeback attempt against the Lions, closing the 37-16 fourth-quarter gap to 40-32 before an onside kick attempt failed. Any suggestion he's "ice cold," though, is now just blowing hot air.

The truth is, Cutler's still prone to all the same mistakes, which means it may finally be time for the Bears to find somebody different.